Re: [PATCH V3 0/7] riscv: Add GENERIC_ENTRY, irq stack support

[Guo Ren]

On Wed, Sep 7, 2022 at 1:42 AM <Conor.Dooley@xxxxxxxxxxxxx> wrote:
>
> On 06/09/2022 04:54, guoren@xxxxxxxxxx wrote:
> > From: Guo Ren <guoren@xxxxxxxxxxxxxxxxx>
> >
> > The patches convert riscv to use the generic entry infrastructure from
> > kernel/entry/*. Add independent irq stacks (IRQ_STACKS) for percpu to
> > prevent kernel stack overflows. Add the HAVE_SOFTIRQ_ON_OWN_STACK
> > feature for the IRQ_STACKS config. You can try it directly with [1].
>
> Hey Guo Ren,
> I applied this patchset to v6.0-rc4 & ran into a build error:
> /stuff/linux/arch/riscv/kernel/entry.S:347:9: error: operand must be a bare symbol name
>  la a3, ((1 << (12)) << (2 + 0))
Yes, please try:
-       la      a3, IRQ_STACK_SIZE
+       li      a3, IRQ_STACK_SIZE

la is for the symbol, not immediate. But why does my toolchain not
report the error?

➜  linux git:(generic_entry_v3) make ARCH=riscv
CROSS_COMPILE=riscv64-unknown-linux-gnu- EXTRA_CFLAGS+=-g
O=../build-riscv/ -kj62 all -kj
➜  linux git:(generic_entry_v3) riscv64-unknown-linux-gnu-gcc -v
Using built-in specs.
COLLECT_GCC=riscv64-unknown-linux-gnu-gcc
COLLECT_LTO_WRAPPER=/opt/riscv/libexec/gcc/riscv64-unknown-linux-gnu/11.1.0/lto-wrapper
Target: riscv64-unknown-linux-gnu
Configured with:
/home/guoren/source/riscv-gnu-toolchain/riscv-gcc/configure
--target=riscv64-unknown-linux-gnu --prefix=/opt/riscv
--with-sysroot=/opt/riscv/sysroot --with-pkgversion=g5964b5cd7272
--with-system-zlib --enable-shared --enable-tls
--enable-languages=c,c++,fortran --disable-libmudflap --disable-libssp
--disable-libquadmath --disable-libsanitizer --disable-nls
--disable-bootstrap --src=.././riscv-gcc --enable-multilib
--with-abi=lp64d --with-arch=rv64imafdc --with-tune=rocket
--with-isa-spec=2.2 'CFLAGS_FOR_TARGET=-O2   -mcmodel=medlow'
'CXXFLAGS_FOR_TARGET=-O2   -mcmodel=medlow'
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 11.1.0 (g5964b5cd7272)



>         ^
>   CC      arch/riscv/kernel/process.o
> make[5]: *** [/stuff/linux/scripts/Makefile.build:322: arch/riscv/kernel/entry.o] Error 1
> make[5]: *** Waiting for unfinished jobs....
>
> Thanks,
> Conor.
> >
> > [1] https://github.com/guoren83/linux/tree/generic_entry_v3
> >
> > V3:
> >  - Fixup CONFIG_COMPAT=n compile error
> >  - Add THREAD_SIZE_ORDER config
> >  - Optimize elf_kexec.c warning fixup
> >  - Add static to irq_stack_ptr definition
> >
> > V2:
> >  Link: https://lore.kernel.org/linux-riscv/20220904072637.8619-1-guoren@xxxxxxxxxx/
> >  - Fixup compile error by include "riscv: ptrace: Remove duplicate
> >    operation"
> >  - Fixup compile warning
> >    Reported-by: kernel test robot <lkp@xxxxxxxxx>
> >  - Add test repo link in cover letter
> >
> > V1:
> >  Link: https://lore.kernel.org/linux-riscv/20220903163808.1954131-1-guoren@xxxxxxxxxx/
> >
> > Guo Ren (7):
> >   riscv: elf_kexec: Fixup compile warning
> >   riscv: compat_syscall_table: Fixup compile warning
> >   riscv: ptrace: Remove duplicate operation
> >   riscv: convert to generic entry
> >   riscv: Support HAVE_IRQ_EXIT_ON_IRQ_STACK
> >   riscv: Support HAVE_SOFTIRQ_ON_OWN_STACK
> >   riscv: Add config of thread stack size
> >
> >  arch/riscv/Kconfig                    |  19 ++
> >  arch/riscv/include/asm/csr.h          |   1 -
> >  arch/riscv/include/asm/entry-common.h |   8 +
> >  arch/riscv/include/asm/irq.h          |   3 +
> >  arch/riscv/include/asm/ptrace.h       |  10 +-
> >  arch/riscv/include/asm/stacktrace.h   |   5 +
> >  arch/riscv/include/asm/syscall.h      |   6 +
> >  arch/riscv/include/asm/thread_info.h  |  19 +-
> >  arch/riscv/include/asm/vmap_stack.h   |  28 +++
> >  arch/riscv/kernel/Makefile            |   1 +
> >  arch/riscv/kernel/elf_kexec.c         |   2 +-
> >  arch/riscv/kernel/entry.S             | 255 +++++---------------------
> >  arch/riscv/kernel/irq.c               |  75 ++++++++
> >  arch/riscv/kernel/ptrace.c            |  41 -----
> >  arch/riscv/kernel/signal.c            |  21 +--
> >  arch/riscv/kernel/sys_riscv.c         |  27 +++
> >  arch/riscv/kernel/traps.c             |  11 ++
> >  arch/riscv/mm/fault.c                 |  12 +-
> >  18 files changed, 259 insertions(+), 285 deletions(-)
> >  create mode 100644 arch/riscv/include/asm/entry-common.h
> >  create mode 100644 arch/riscv/include/asm/vmap_stack.h
> >



-- 
Best Regards
 Guo Ren